Referring to FIG. 1, a schematic view of a conventional sealed equipment cabinet is illustrated. The sealed equipment cabinet 1 is employed for isolating the internal electronic components (not shown) from the adverse environmental conditions such as rain, humidity, dust and pollutants in order to extend the operational lives of the electronic components. As known, the internal electronic components may generate heat during operation, which is readily accumulated around the circuit board and difficult to dissipate away. If the sealed equipment cabinet 1 fails to transfer enough heat to the ambient air, the elevated operating temperature may result in damage of the electronic components, a breakdown of the whole sealed equipment cabinet 1 or reduced operation efficiency. For maintaining a normal working temperature, a heat exchanger 10 is provided on the back side of the sealed equipment cabinet 1 to remove most heat accumulated in the sealed equipment cabinet 1.
The heat exchanger 10 principally comprises an upper fan 11, a lower fan 12, a plurality of spaced heat sink fins 13, a partition plate 14, an external air inlet 15, an external air outlet 15′, an internal air inlet 16, an internal air outlet 16′ and a crooked heat pipe 17. The upper fan 11 and the lower fan 12 are in fluid communication with the ambient air and the inside portion of the sealed equipment cabinet 1, respectively. The partition plate 14 is extended from the inner wall of the heat exchanger 10 such that the heat exchanger 10 is partitioned into an upper receptacle 101 and a lower receptacle 102. The heat sink fins 13 have thereon several perforations (not shown). The crooked heat pipe 17, which contains cooling fluid therein, is penetrated through the perforations of the heat sink fins 13 and tightly bound to the fins 13.
The heat dissipation mechanism of the heat exchanger 10 will be illustrated as follows in more details.
First of all, the hot air H1 generated from the electronic components inside the sealed equipment cabinet 1 is pumped by the lower fan 12 to the lower receptacle 102 through the internal air inlet 16. The hot air H1 is then conducted to the heat sink fins 13 and the heat pipe 17, so that a portion of heat of the hot air H1 is transmitted to the upper receptacle 101 and a cooled air C1 is returned to the sealed equipment cabinet 1 through the internal air outlet 16′. At the same time, the ambient cooling air C2 is pumped by the upper fan 11 to the upper receptacle 101 through the external air inlet 15. The cooling air C2 is then conducted to the heat sink fins 13 and the heat pipe 17 to remove a further portion of heat from the heat sink fins 13 and the heat pipe 17. Meanwhile, a heated air H2 is exhausted to the surroundings through the external air outlet 15′.
Although the heat exchanger 10 shown in FIG. 1 may remove a portion of heat generated from the electronic components inside the sealed equipment cabinet 1, there are still some drawbacks. For example, if the heat exchanger 10 has been operated for an extended time period, the heat pipe 17 is likely ruptured and the cooling fluid contained therein will be leaked out. Under this circumstance, the overall heat exchange efficiency of the sealed equipment cabinet 1 is largely reduced. For increasing heat-dissipating efficiency, the combination of the heat pipe 17 and the heat sink fins 13 should be refreshed because the sealed equipment cabinet 1 has only one heat pipe 17. It is costly and time-consuming to refresh the combination of the heat pipe 17 and the heat sink fins 13.
Please refer to FIG. 1 again. Since the lower fan 12 is very close to the internal air inlet 16, the cooled air C1 is rapidly returned to the sealed equipment cabinet 1 through the internal air outlet 16′ simultaneously after the hot air H1 is pumped by the lower fan 12 to the lower receptacle 102 through the internal air inlet 16. Under this circumstance, a portion of cooled air C1′ is likely to reflow under the heat sink fins 13 and in the vicinity of the internal air inlet 16, in which the cooled air C1′ is mixed with the hot air H1. The interference between the cooled air and the hot air may impair the heat exchange efficiency of the heat exchanger 10. Similarly, since the upper fan 11 is very close to the external air inlet 15, the heated air H2 is rapidly exhausted to the surroundings through the external air outlet 15′ simultaneously after the cooling air C2 is pumped by the upper fan 11 to the upper receptacle 101 through the external air inlet 15. Under this circumstance, a portion of heated air H2′ is likely to reflow above the heat sink fins 13 and in the vicinity of the external air inlet 15, in which the heated air H2′ is mixed with the cooling air C2. The interference between the heated air and the cooling air may also impair the heat exchange efficiency of the heat exchanger 10.
Referring to FIG. 2, a schematic view of another conventional heat exchanger used in a sealed equipment cabinet is illustrated. The heat exchanger 20 is disposed at the top side of the sealed equipment cabinet 2. The heat exchanger 20 principally comprises an upper fan 21, a lower fan 22, a plurality of spaced heat sink fins 23, a top air inlet 25, a bottom air outlet 26 and a plurality of spaced heat pipe 27. The upper fan 21 and the lower fan 22 are in fluid communication with the ambient air and the inside portion of the sealed equipment cabinet 2, respectively. By the top surface of the sealed equipment cabinet 2, the heat exchanger 20 is partitioned into an upper receptacle 201 and a lower receptacle 202. The heat sink fins 23 have thereon several perforations (not shown). The heat pipes 27, which contain cooling fluids therein, are penetrated through the perforations of the heat sink fins 23 and tightly bound to the fins 23. In comparison with the heat exchanger 10 as shown in FIG. 1, the heat pipes 27 of the heat exchanger 20 shown in FIG. 2 are perpendicular to the heat sink fins 23. In addition, since more heat pipes 27 are used, the heat exchanger 20 may normally operate even if only a small number of heat pipes 27 are damaged. The heat dissipation mechanism of the heat exchanger 20 is similar to that described in the heat exchanger 10 of FIG. 1, and is not redundantly described herein.
Please refer to FIG. 2 again. Since the lower fan 22 is very close to the bottom air outlet 26, the cooled air C1 is rapidly returned to the sealed equipment cabinet 2 through the bottom air outlet 26 simultaneously after the hot air H1 is pumped by the lower fan 22 to the lower receptacle 202. Under this circumstance, a portion of cooled air C1′ is likely to reflow under the heat sink fins 23 and in the vicinity of the bottom air outlet 26, in which the cooled air C1′ is mixed with the hot air H1. The interference between the cooled air and the hot air may impair the heat exchange efficiency of the heat exchanger 20. Similarly, since the upper fan 21 is very close to the top air inlet 25, the heated air H2 is rapidly exhausted to the surroundings through the top air inlet 25 simultaneously after the cooling air C2 is pumped by the upper fan 21 to the upper receptacle 201. Under this circumstance, a portion of heated air H2′ is likely to reflow above the heat sink fins 23 and in the vicinity of the upper fan 21, in which the heated air H2′ is mixed with the cooling air C2. The interference between the heated air and the cooling air may also impair the heat exchange efficiency of the heat exchanger 20. For increasing the overall heat-dissipating efficiency of the heat exchanger 20, the area and the number of the heat sink fins 23 and the heat pipes 27 should be largely increased. Therefore, the whole volume of the heat exchanger is increased and a large layout space is needed.
In views of the above-described disadvantages resulted from the conventional method, the applicant keeps on carving unflaggingly to develop an improved heat exchanger according to the present invention through wholehearted experience and research.